Turning off 2.4 GHz helps but doesn't fully solve the issue. We turned off 2.4 GHz last summer and have had less complaints about slowness (from connections to distant APs), but still sometimes have to have mac laptops turn airport off and back on to...
As far as I know, Mac OS is supposed to always prefer 5 GHz over 2.4. But in practice, it seems to also like to re-connect to the last AP, instead of the strongest signal, which then may connect using 2.4GHz. Perhaps reducing channelization or power...
